Tetrahalogeno-ortho-aminophenols



l atentec i May 19, 1936 TETRAHALOGENO- ORTHIO -AMINOPHENOLS Max Raeck,Dessau-Haideburg in Anhalt, Germany, assignor to General Aniline Works,Inc., New York, N. Y., a corporation of Delaware No Drawing. ApplicationSeptember 22, 1934, Serial No. 745,101. In Germany November 2,

The present invention relates to a process of manufacturingtctrahalogeno-ortho-aminophenol.

According to Th. Zincke (Berichte der deutschen Chemischen Gesellschaft21 (1888), 2724) the chlorination of Z-amino-l-hydroxybenzenehydrochloride in glacial acetic acid producestetrachlor0-2-amino-l-hydroxybenzene. Investigation has shown, however,that the analyzed proddgclaims. (o1. zoo-430.5)

Example 1.42.5 parts of 3,4,6-trichloro-2- amino-l-hydroxybenzene aredissolved in a solution of 8 parts of solid sodium hydroxide in 1600parts of water and into the solution, at 0-5 C., phcsgene is passeduntil there is no more diazotizable matter present. The separated 2-oxo-4,5,7-trichlorobenzoxazoledihydride-(2,3) of the formula 10 uct is notan individual body but a mixture of the hydrochlorides of several highlychlorinated C ortho-aminophenols. Thus Zincke did not in fact 1* N Hhave in his hands the tetrachloro-ortho-amino- Cl phenol. Later, Buresand I-Iavlinova (Chemisches 15 Zentralblatt 1929, II, 1403) claim tohave pro- I duced tetrachloro-ortho-aminophenol as a byproduct in thesaponification of tetrachloroacetylortho-anisidine with caustic sodalye. A techniis filtered and Washed w t Wat h paste t us cal processmaking t t 1 -2 i 1 obtained is dissolved hot in a solution of 18 parts20 hydroxybenzene h t b d d, h r, of sodium carbonate in 1150 parts ofwater; then on t prior t t at 20 to C.,chlorine is introduced into thesolu- By th present i ti 3,4 5,6-tetraha10gention until the reaction isdistinctly acid to Congo. 2-amino-l hydroxybenzenes are made on a, com-In the Course Of the chlorination the product iS mercial scale in verygood yield and purity by precipitated. When chlorination is complete,the 25 converting the easily accessible 3,4,6-trichloro-2- Whole isheatedfor 0119 110111 130 170 and amino-l-hydroxybenzene by treatmentwithphosthen sodium carbonate is strewn in until brilliant gene into thecorresponding oxazolone,halogenatpaper is powerfully reddened; hereupon5 parts ing thi b d for l chlorinating 11; or of crystallized sodiumsulfite are added and finalbrominating it, so as to obtain the2-oxo-4,5,6,7- ft r irrin for ab A hour, h s i 30tetrachlorobenzoxazoledihydride-(2,3) of the forfiltered The filtrate sac dified While hot until mula there is only a feeble acid reaction toCongo and the separated 2-0xo-4,5,6,7-tetrachlorobenzox- 050:0azoledihydride- (2,3) is filtered.

3| This body is introduced into a solution of 2s 35 O1 '7 NH parts ofsolid sodium hydroxide in 750 parts of 6 water and the Whole is boiledfor 2 hours in a C1 5 To] reflux apparatus. The mixture is mixed withhydrochloric acid until the reaction is quite fee- 01 bly acid to congo,whereupon the precipitated 4.03,4,5,6-tetrachloro--2-amino-l-hydroxybenzene is or the2-oxo-4,5,'7-trichloro-6-bromobenzoxazolefiltered, Washed and dried. Theyield amounts dihydride-(2,3) and finally saponifying the oxato 44parts, which is about 90 per cent. of the zole ring. There is thusobtained 3,4,5,6-tetratheoretical, calculated on thetrichloro-Z-aminochloro-2-amino-1-hydroxybenzene or3,4,6-tril-hydroxybenzene used. 4 chloro 5 bromo 2amino-l-hydroxybenzene. Example 2.-The 2-oxo-4,5,7--trichlorobenzox-These bodies are useful as intermediate products for the manufacture ofdyes and pharmaceutical preparations.

The following examples illustrate the invention, the parts being byWeight:-

parts of water.

35 parts of bromine are then allowed to drop into the solution and thewhole is heated after 2 hours at 85 C., and the product worked up asdescribed in Example 1. The 2 oxo--4,5,'7-trich1oro-6bromobenzoxazoledihy- 5 dride-(2,3), which melts at 266 C., issaponified as described in Example 1 and there is obtained in thismanner a good yield of 3,4,6-trichloro-5-bromo-2-amino-l-hydroxybenzene.

What I claim is: 10 1. The process which comprises reacting 3,4,6-trich10ro-2-amino-l-hydroxybenzene with phosgene to form the oxazole ofthe formula OT=O 01 NH 25 halogenating this compound and saponifying theoxazole ring.

2. The process which comprises reacting 3,4,6-

trichloro-Z-amino-l-hydroxybenzene with phosgene to form the oxazole ofthe formula.

-c= 01 NH 5 1 chlorinating this compound and saponifying the oxazolering.

3. The process which comprises reacting 3,4,6-trichloro-Z-amino-l-hydroxybenzene with phosgene to form the oxazole ofthe formula brominating this compound and saponifying the oxazole ring.

4. 3,4,6-trich1oro 5 bromo 2 amino-l-hydroxybenzene;

MAX RAECK.

